The only known structure currently used for multiplying charge on a charge-coupled device and producing a product represented by a charge is a structure designed by Jerome J. Tiemann and W. E. Ehgeler of the General Electric Co., in Schenectady, New York. It has the limitation for many applications that the multiplication is fixed when the device is fabricated and cannot be changed. Therefore, the device is only useful when multiplication by a fixed reference is required, in contrast to the invention described herein.
Charge coupled semiconductor devices have been described in the prior art since at least April 1970. The basic principles of these devices are described by W. S. Boyle and G. E. Smith in the April 1970 issue of The Bell System Technical Journal of April 1970, in an article entitled Charge Coupled Semi-Conductor Devices. The physical parameters to build such devices as well as typical materials, for example a silicon-silicon dioxide MOS structure, are described therein. Additional information is furnished in the same issue of the Journal in an article entitled Experimental Verification of the Charge Coupled Device Concept, by G. F. Amelio, N. F. Tompsett and G. E. Smith.